Press loader and shutter



June 10, 1952 R. CHAPMAN PRESS LOADER AND SHUTTER 5 Sheets-Sheet 1 FiledApril 10, 1948 I l INVENTOR.

pk Chapman June 10, 1952 CHAPMAN 2,599,693

PRESS LOADER AND SHUTTER Filed April 10, 1948 5 Sheets-Sheet 2 vINVENTOR. Ralph Chapman June 10, 1952 R. CHAPMAN PRESS LOADER ANDSHUTTER 5 Sheets-Sheet 3 Filed April 10, 1948 INVENTOR. Pg /,0// Chapmand /WW fl/fa rr/E/ June 10, 1952 R. CHAPMAN PRESS LOADER AND SHUTTER 5Sheets-Sheet 4 Filed April 10, 1948 June 10, 1952 CHAPMAN 2,599,693

PRESS LOADER AND SHUTTER Filed April 10, 1948 5 Sheets $heet 5 Fji I/Z6//U /ZZ '-z-' 75' /27 /2/ 2 4 24 f7 INVENTOR. A33 Ralph ChapmanPatented June 10, 1952 PRESS LOADER AND SHUTTER Ralph Chapman,Corvallis, Oreg., assignor to Chapman Forest Utilization, Ina,Corvallis, 0reg., a corporation of Oregon Application April 10, 1948,Serial No. 20,335

10 Claims.

My present invention comprises a press loading device for a fibre boardmachine whereby automatic production of artificial boards at high speedis accomplished.

In the art of forming fibre boards a wet mat of fibre formed from wood,straw, waste paper, or other cellulosic material, with or without addedbinding substances such as phenolic resins, may be inserted betweenplatens of a press capable of compressing and heating the mats to form acon solidated board from the loose fibre mat. Production of such mats isaccomplished on a variety of machines such as the Fourdrinier type, thecylinder type, or the deckle box type machine, in all instances thefibre being deposited upon a screen or the like by the application ofsuction to the opposite side of the screen to withdraw water from a thinslurry of fibre. After formation of thev wet mat it is usually squeezedor otherwise compressed at lower temperatures to express most of thefree water from between the fibres so as to create a tangled mat offibres at about 50% saturation. After such operation the mat is 001mpressed and heated to varying extents to create artificial boards ofvarious densities and thicknesses. The present invention is concernedwith the final step of heating and compressing the partially wet mat.

A serious problem in the manufacture of artificial boards is the loadingand unloading of the heating press. The mat, for the formation of aboard having a density of one and a thickness of approximately 4 inch,may be as much as two inches thick after it has been released from thecold press and the fibres have sprung back as much as their characterwill permit. Usually such boards are made in commercial sizes, such as4' x 8, so that the mat is easily disrupted. In order to heat and pressthe wet mat properly a period of time ranging" from five to twenty-fiveminutes is usually allowed, on the average about fifteen minutes. Matscan be formed faster than one every fifteen minutes so multiple platenheating presses have been developed, each capable of holding, forexample, twenty wet mats and simultaneously consolidating them intoboards. Therefore, if the consolidating operation requires twentyminutes, a twenty unit press can keep up with the output of a formingmachine capable of creating one mat every minute. The diificulty.however, has been to load the mats into the forming press at a speedcommensurate with the ability of the consolidating machine. Theprincipal object of my present invention is to provide means for loadingmats into a consolidating press iii 2 as fast as they can be formed bythe forming machine without endangering the wet mats while they arebeing handled.

With my invention mats can be formed at the rate of one every thirty orforty seconds and loaded into a consolidating press operating on fifteento twenty minute cycles without necessarily interrupting the formingoperation.

An object of the present invention is to provide means to store wet matsas they are formed in an accumulator rack positioned between the matforming machine and the consolidating press, such accumulator rack beingso constructed and arranged as to receive mats at spaced intervals fromthe forming machine and position them opposite the platens of theconsolidating press.

A further object of the present invention is to provide meansautomatically to control the operation of the accumulator rack whereby aplurality of storage trays or the like are presented successively at thelevel of the forming screen and into which the mats are fed duringintermittent movements of the forming screen.

A further object of the present invention is to provide meansautomatically to deliver a plurality of wet mats stored in theaccumulator rack simultaneously into the consolidating press.

A further object of the present invention is to provide means to protectwet mats stored in the accumulator rack adjacent the press from theeffect of heat radiated from, and steam escaping from, the consolidatingpress. It is desirable to subject all areas of a wet mat to the sameconditions at all times and a drawback in the use of accumulator rackshas been that the ends of mats adjacent the consolidating press havebeen subjected to drying heat and steam prior to the subjection of theremainder of the mat thereto. My invention provides automaticallyoperating shielding means to prevent radiation and steam from theconsolidating press from reaching wet mats in the accumulator rack.

The foregoing. and other objects and advantages of the present inventionwill be more readily ascertained by inspection of the followingspecifications taken in connection with the accompanying drawingswherein like numerals refer to like parts throughout while the featuresof novelty will be more distinctly pointedout in the appended claims.

In the drawings:

Fig. 1 is a vertical section through a portion of a board manufacturingplant taken at one side of the accumulator rack and showing the relationthereto of the board forming equipment and the consolidating press;

Fig. 2 is a plan view on an enlarged scale of the accumulator rack ofthe present invention;

Fig. 3 is a detail View on an enlarged scale taken substantially alongline 33 of Fig. 1;

Fig. 4 is a horizontal section on an enlarged scale taken along line 4-4of Fig. 1;

Fig. 5 is a vertical section on an enlarged scale taken substantiallyalong 1ine 5-5 of Fig. 2;

Fig. 6 is a vertical section taken substantially along line B6 of Fig.1;

Fig. '7 is an end view of the pusher illustrated in Fig. 6;

Fig. 8 is a vertical section on an enlarged scale taken substantiallyalong line 8--8 of Fig. 2;

Fig. 9 is a vertical section on an enlarged scale taken substantiallyalong line 9-9 of Fig. 1;

Fig. 10 is a sectional view taken substantially along line 10-40 of Fig.9;

Fig. 11 is a vertical section taken along line ll-H of Fig. i;

Fig. 12 is a vertical section taken along line 12-42 of Fig. 11;

Fig. 13 is a schematic representation showing Fig. 16 is a similar viewshowing the operation of the pusher to start wet mats into theconsolidating press;

Fig. 17 shows the completion of the movement of the mats into theconsolidating press;

Fig. 18 is a similar view showing the arrangement of the consolidatingpress with respect to the accumulator rack of the present invention andan unloading mechanism at the far end of the press;

Fig. 19 is a schematic view showing a portion of a control device;

Fig. 20 is a similar vlew showing another portion of the control device;and

Fig. 21 is a. schematic representation of a control circuit embodied inthe present device.

Although many different types of intermittently movable mat formingmachines may be associated with the present invention, reference ishereby made to my copending application, Ser. No. 20,334, filedconcurrently herewith, in which such a machine is illustrated andclaimed. For the present invention it is sufficient to set forth thatwet mats are fed forwardly by an intermittently movable conveyor orforming screen having a working flight 20 and a return flight 2!, theconveyor passing about a feeding drum 22 mounted on a shaft 23 near theend of a frame 24. The frame 24 extends beyond the drum 22 and isprovided with a plurality of idler rolls 26 spaced closely together soas to support the wet mat when moved forwardly thereover by the screenor conveyor which remains in contact with the rearward portion of thewet mat until all of the mat has passed beyond the drum 22. Intermittentmovement of the conveyor may be accomplished by any suitable automaticor manual control means as set forth in the foregoing application.

The frame 24 overhangs a pit 30 of substantial size and depth extendingbeneath the level of thereof adjacent the forming machine.

the feeding flight 20. An accumulator rack is vertically guided formovement from and into the pit 33 by four guide posts 31 suitablymounted within the pit and maintained in spaced relationship by a bottomframe 32 and a top frame 33 located at a considerable height above thelevel of the working flight 20. A suitable form of post for the purposeis herein illustrated, the same comprising a length of steel or castiron pipe of large diameter such as six to eight inches. The accumulatorrack 34 comprises a lower frame 35, an upper frame 36 and vertical sidemembers 31, 38, 39 and 40. The distance between the upper and lowerframes is such that a plurality of roller trays 4! corresponding innumber to the number of platen spaces of the consolidating press to beserved may be located therebetween as shown in Fig. 1. In order to guidethe accumulator rack 34 in its movement each upper and lower cornerthereof is provided with a guide bracket 42, a part of which comprises ahorizontal plate having a substantially semi-circular notch 43 thereinof substantially the same diameter as the tubular guide post. The plateprojects forwardly in position to embrace the post 3| with the outersurface thereof received in the notch 43. Each of the notches 43 has aplurality of smaller notches 44 therein which prevent the plate fromscraping lubricant entirely toward the top and bottom of the posts.There will always be some lubricant distributed along the posts invertical streaks as permitted by the small notches 44.

Each roller tray 41, as is clearly seen in Figs. 9 to 12, inclusive,comprises a side channel member 45 between which are mounted a pluralityof closely spaced rollers 46 extending transversely of the tray. As seenin Fig. 3, the rollers 46 each comprise a length of light weight metaltubing, into the open ends of which are pressed the outer raceways 41 ofball bearing assemblies. the inner raceways 48 thereof being mountedupon the reduced inner ends of threaded studs 49 passing through nuts 50welded to the member 45 and retained in adjusted position by lock nuts5| as shown. Each of the rollers 45, therefore, turns very freely with aminimum amount of frictional resistance. As seen most clearly in Fig. l,the trays 4! are arranged at a slight incline extending downwardly fromthe ends Therefore, as seen in Figs. 13 and 14, when a. wet. mat is fedforwardly onto one of the trays and its rear end has passed beyond theend of the working flight 20, the mat will proceed completely into theaccumulator rack due to its own m0- mentum.

At the far end of the rack there is provided a shutter comprisinginwardly facing fixed channel members extending horizontally across thespace between the upright members 49. The top of each channel member isat or slightly below the level of the last roller 46 and the bottomthereof is spaced above the next lower set of rollers to leave a gapwide enough to permit free passage of the thickest mat formed. Thechannel members 60 constitute fixed vanes or members forming a partialscreen across the far end of the accumulator rack for partiallyshielding the ends of wet mats thereon from the consolidating pressindicated at 6 I Movable vanes cooperatin with the fixed vanes may bemoved to closed position to create an imperforate wall or shield betweenthe consolidating press and the wet mats, such movable vanes, preferablycomprising. facing channel bars. 62 ofsubstantially thezsame: size asthe: channel bars 00. The ends of bars 62 extend beyond the. ends ofbars 00,. as. seen in;Figs. 9. and 11, and are mounted upon a. pair ofslides preferably comprising lengths of tube 63, slidably mounted uponvertical guide rods. 84. extending between the frames 35 and 36:. Thetubes 03 are shorter than. the rods I34 and. both ends of each rod 04project beyond the tube 63. The lower end of rod 64. is provided with atransverse crosshead 65 receivable between the arms of a short channelmember 65 having open jaws at one side. Crossheads 55 are preferablyhollow and internally threaded in order that studs TI may be receivedtherein to clamp the lower end of the rod in position. The upper end ofeach rod. is threaded and received in an internally threaded capstanmember 68 which is rotatably mounted in a bracket 89 suspended from acorner of the upper frame 35. The capstan member 68 may be. turned toadjust the tension of rod 64.

Inorder to control the relative position of the fixed and movable vanesthe lower end of the tube 63 has welded thereto an extension rod "I0which passes through holes in the lower frame 35, the rod being of suchlength as to strike a fixed abutment such as the floor of the pit 30shortly before the rack reaches its lower limit of movement. control ofthe descending movement of the rack iscoupled with the upward movementof the movable. vanes as accomplished by the extension 10 so that whenthe movable vanes bridge the gaps. between the fixed vanes, therack willcome 7' to. rest. Such means are not herein disclosed as behig obviouslywithin the skill of the ordinary person skilled in the art. The upperend of one of the. tube 63 is provided with a laterally extendingbracket I in which i mounted a transverse keeper I6 capable of beingreceived in the hook of a latch 11 pivotally mounted upon the bracket 68and having a cam face at its lower extremity. The latch 11 comprises abell crank,

the crank arm of which is pivotally connected to. the upper end of anarmature 79 forming a movable core. for a solenoid 80 mounted upon abracket extension of the frame 35. The lower end of armature 19 has alimiting enlargement BI thereon to prevent the armature from passingupwardly through the solenoid beyond a limited extent, and a weight 82may be attached thereto to assure its descent when the solenoid isdeenergized. Upon upward movement of the tube 63, the keeper 16 strikesthe cam face It and rocks the latch TI outwardly until the latch isfree: to snap back and hold the movable vanes in elevated position. Themovable vanes will be held in closed. position until solenoid S0 isenergized to release. thelatch whereupon the movable vanes will dropuntil arranged opposite. the fixed vanes. When the movable vanes are inscreening position they form stops against which the wet mats come torest after being fed into the accumulator rack.

The rack. is intermittently moved upward the distance. between traysbetween each intermittent movement of the forming machine conveyor untilthe rack reaches the upper limit of its movement and isunloaded,whereupon it is rapidly returned to its. lower position as seen inFig. 1. Movement of the rack is accomplished by the following mechanism.

A motor 83 is mounted upon the top frame 33 and belt-connected to theshaft of a reduction Means may be provided whereby gear mechanism. 85-.The. shaft; 86. from the mechanism 85 is fixed to the driven member-ofany suitable clutch 81, the, driven. member of which is splined: to; a.stub shaft 88 supported transversely of the center of the frame in.journals 89.. A pair of sprockets 90- are fixed to the shaft 88 betweenthe journals 89. The movable element of clutch 81. is fastened to ashifting collar 9| which is embraced between the arms of a.yoke lever92' pivotally-mounted upon a bracket 93 extending from one of thejournal supports. The lower end of yoke lever 92 is connected to thearmature 84 of a solenoid 95. Upon energization of solenoid S5 the lever92 is rocked to engage the clutch and vice versa. Details of the clutchare not given since many such devices are readily procurable. Each ofthe sprockets 90 drives a sprocket chain 91 which extends toward one endof the frame and passes about a sprocket 98 fixed to a shaft 99journaled on the top of the frame. The outer ends of each shaft 99support sprockets I00 about which pass elevator sprocket chains IOIhaving three supporting lengths. One end of the chain I M is fastened tothe frame 33. The chain then passes downwardly about an idler sprocketI02 mounted at a corner of the accumulator rack frame 36, then upwardlyabout the sprocket I00, then downwardly into the supporting column 3Iand i attached to a heavy weight I04 slidably guided therein. The fourweights I04 counterbalance the accumulator rack to some extent but theirmain function is to keep the chains I M taut. Movement of sprockets I00counterclockwise is simultaneously accomplished by operating motor 03when shaft 86 is clutched to stub shaft 88, thereby elevating theaccumulator rack 34. Releasing the clutch will permit the rack to droprapidly to the bottom of the pit.

Schematic means are set forth in Figs. 19, 20 and 21 for controlling themotor 83 and the clutch 81. At the far end of the overhanging portion offrame 24 there is provided a cross shaft I07 which extends parallel tothe rollers 26. An intermediate portion of the shaft I01. carries asensing plate I09 which projects upwardly into the path of the wet mats55. The shaft I01 has a movable contact arm I08 thereon which isengageable with a fixed contact H0. The shaft I0! is lightly weighted asby means of an eccentric weight I I I which exerts counterclockwiseforce tending to keep the contacts I09 and H0 engaged until released bythe mat 55 rocking the plate I09 forward. The eccentricity of weight IIIis such that the sensing plate will be rocked back to its projectingposition as soon as the end of the mat 55 passes beyond the plate. Acollar I I2 loosely surrounds a portion of shaft I01 and iseccentrically weighted as by an arm II3 so positioned as to pass beyondthe vertical toward each side. The shaft I01 has a stud H4 projectingtherefrom which is engageable beneath a pin I I 5 on collar I I2. Thecollar I I2 also carries a contact arm H6 which is engageable with afixed contact II! when the weight H3 is thrown clockwise beyond thevertical by rotation of shaft I01 due to the depression of sensing plateI09. The weight II3 will hold the contacts IIS and II? closed eventhough shaft I01 reverses when contact plate I09 is released from themat 55. The projecting end of contact arm IIG extends sufficiently whenrocked forward to be engaged by a series of lugs II8 projecting from theframe member 37 and spaced apart corresponding to the spacing of therack roller shelves.

The control circuit embodies a motor controlling line I in which the twosets of switch contacts I08I Ill and IIfi-I I1 are placed in series.When a mat is moved forward from the forming machine or conveyor, thesensing plate I09 is rocked to move contact I88 from contact II 0, thusbreaking the circuit to motor 83. This is instantaneously succeeded bycontact I It being moved into engagement with fixed contact III, but thecircuit to motor 83 remains broken until the mat is almost entirely intothe accumulator rack and sensing plate I09 is released. Motor 83 is nowenergized to move the rack slowly upward. One of the lugs II8 sooncontacts the outer end of arm IIG to break the circuit to the motor andthereby bring the rack to rest, the lug II8 being so placed that thenext lower, empty,

roller tray will be in position to receive the succeeding mat.

The solenoid 95 is controlled by a switch I2I in a line I22, the switchbeing moved to its open position by means (not shown) actuated when thepress is filled. The switch |2I is normally closed so that the clutchnormally remains engaged, thus holding the rack at the positions towhich it is moved intermittently by the motor 83. The weight of the rackvaries as the successive mats are loaded therein and the clutch is thesole means for preventing the rack from returning to the bottom of thepit. The reduction drive from the motorcauses relative slow upwardmovement of the rack at each step, but

if the clutch is disengaged the rack will drop rapidly to the bottom ofthe pit. In order to arrest the rack at the bottom of its movement theswitch I2I is opened by means (not shown) associated with the rack,whereupon the clutch is engaged and the successive operations of themotor will thereafter cause intermittent upward movement. In order thatthe rack may be returned at any time a manual switch I23 is positionedin a jumper circuit I24 whereby the clutch may be disengagedindependently of the opera- .1

When the filled rack has been arrested at its uppermost position and themovable shutter vanes dropped, the mats will remain in the accumulatorrack since the incline of the roller trays is not great enough to permitthe mats to move forwardly, at least without an initial im petus havingbeen given to the mats.

The pusher comprises a frame including a pair of vertical channel bars130 depending from a pair of slightly inclined channel bars I EIarranged parallel to the inclined roller trays. The bars I3I extendbeyond the bars 13% and are braced by angularly extending bars I32. Aplurality of pusher rods I33 extend inwardly in vertically spaced pairs,each pair being aligned with the space between adjacent roller tray whenthe rack is resting at its uppermost position. A pusher plate I 34 isbent around and fastened to the inner ends of each pair of arms I33 topresent a wide fiat surface adjacent the rear end of each of the wetmats resting on the roller trays. Bars I3I extend inwardly beneath theupper frame 33 and are so formed as to constitute toothed racks as, forexample, by having long, toothed members I35 welded to the lowersurfaces thereof. A guide member I31 is welded 8 to the upper surfaceand similar guide members are welded at each end of the toothed memberI35 on the lower surface. A plurality of spaced pairs of supportingchannel bars I depend from portions of the frame 33 and journaltransverse idler shafts, a plurality of such shafts being located abovethe rack bar I3I and a plurality below. The upper row supports aplurality of flanged guide wheels I4I shaped to receive the guide barsI31. The outer pair of lower shafts I3I support similar guide wheels toengage the guide bar sections on the lower flange of the rack bar. Apair of angle bars I43 extend transversely between the lower ends of theintermediate pair of supporting bars to provide a support for a motorI44 which is connected to a transverse shaft I45 extending between theopposed supports and keyed to both of a pair of gears I42 engaging therack bars so that they may be moved simultaneously and co-extensively bythe motor I44. When the rack is at the top of its movement, motor I44may be driven for a short period in a direction to throw the rack barsI3I inwardly and thereupon reversed to position the pusher plates I34beyond the rack as seen in Fig. l. A slight movement is all that isnecessary to overcome the inertia of the wet mats and cause them tocommence moving outwardly through the openings in the shutter when themovable vanes have been moved to open position. Any suitable manual orautomatic means may be provided for accomplishing such movement of therack bar motor provided the movement is prevented unless the platens ofthe consolidating press have been opened to permit reception of the wetmats. A switch I21 in lin I22 is held open by suitable means (not shown)to prevent release of the clutch until the mats have left the rack. Theextent of movement of the pusher is illustrated in Figs. 18 and 17.

In order to ensure complete withdrawal of the wet mats from theaccumulator rack and insertion thereof into the platens, suitable meansmay be provided to engage the leading edge of each mat and draw it intothe press. Such means may be formed as illustrated, described andclaimed in my copending application, Ser. No. 20,336, filed concurrentlyherewith. For the purpose of this application Figs. 13 to 18, inclusive,illustrate so much of the press as is necessary for an understanding ofthe present invention. In Fig. 13 it is seen that the platens I havebeen moved to closed position in which pressure and heat is beingapplied to compress and consolidate the mats into boards. Each platenpreferably has associated therewith a pair of sprockets I5! at each end,about each pair of which is extended a platen feeding chain I52. Whenthe platens are closed or moving to closed or open position, the chainsI52 are at rest and a screen or other traveling member is positionedbetween the opposite chains, at least between the lower platen and thewet mat or consolidated board lying thereon. In Fig. 15 the rack hasbeen almost filled and is going up to its last position or nearly so.Time has been allowed for complete treatment of the material in theconsolidating press, and the platens are moving to open position, beingcaused to do so by means well known in the art. In Fig. 16, the rack hascome to rest at its uppermost position and the movabl vanes have droppedto open the shutter, the platens are fully open, and the pusher iscommencing to move into the accumulator rack. In Fig. 17 the pusher hasreached its innermost position and is commencing to move outwardly whilethe mat-55 continues to move from the accumulator rack into the presspartly due to its inertia of movement and partly due to the forward pullthereon of the screen or other member lying between the chains 152,which has been caused to move forwardly in synchronism with the movingwet mat as detailed in the copending application mentioned above. InFig. 18, the chains 52 have come to rest with the mat in position to becompressed between the platens, and the accumulator rack has beenlowered to its lower position thereby causing the shutter to becomeclosed. Also this figure illustrates a portion of an unloader racl:positioned at the opposite side of the press, details of which areillustrated, described and claimed in my copending application, Ser. No.20,337, filed con,- currently herewith. In this application it issufficient to state that an unloader rack having a plurality of traysl!) (Fig. 18) is so positioned as to receive the formed boards from thepress as fully set forth in said application, Ser. No. 20,337. Aplurality of fixed vanes IE1 forming a part of a shutter and a pluralityof movable vanes I62 span the gaps therebetween when the press isoperating as seen in Fig. 17.

Having illustrated and described a particular embodiment of my inventionI claim as my invention all modifications and arrangements as comewithin the true spirit and scope of the appended claims.

I claim:

1. -A fibre board machine comprising intermittently movable feedingmeans on which wet mats of fibre may be supported and fed forwardly, avertically and intermittently movable accumulator rack at the forwardend of said feeding means for receiving said mats and holding them forsubsequent insertion into an adjacent hot press, said accumulator rackincluding a plurality of superimposed trays each adapted to receive andhold an individual mat fed thereonto from said means, and a shuttermounted on the forward end of said rack including a plurality ofparallel, spaced apart, stationary slats and a plurality of other slatsmovable from alignment with said stationary slats to bridge the gapsbetween said stationary slats whereby mats in said rack may be protectedagainst steam and hot water issuing from said press.

2. A fibre board machine comprising mat feeding means on which wet matsof fibre may be-fed forwardly, an accumulator rack at the forward end ofsaid feeding means for receiving said mats and holding them forsubsequent insertion into an adjacent hot press, said accumulator rackincluding a plurality of superimposed trays each adapted to receive andhold an individual mat fed thereonto from said mat feeding means, and ashutter mounted on the forward end of said rack including a plurality offixed slats extending horizontally and spaced apart to define a'horizontal gap at the forward end of each tray and a plurality ofintercomiected, vertically movable slats adapted to move from and toopen positions aligned with said fixed slats and shut positions bridgingthe gaps between said fixed slats whereby mats in said rack may beprotected against steam and hot water issuing from said press.

3. A fibre board machine comprising a conveyor movable intermittently atregular intervals and on which wet mats of fibre may be supported andmoved forwardly, an accumulator rack at the forward end of said conveyorincluding a plurality of superimposed trays each adapted to receive andhold an individual mat fed thereonto from said conveyor, 2.shuttermounted on the forward end of said rack including a plurality ofhorizontally extending, immovable slats defining a slot atthe forwardend of each tray and movable slats adapted to move from and to openpositions aligned with said fixed slats and shut positions bridging theslots between said fixed slats, means intermittently to-move said-rackyer..- tically in short steps in one direction whereby each tray mayreceive a mat from said conveyor, means to move said rack back to itsstarting point in one continuous movement, means to moveisaid movableslats to shut positions upon return of said rack, means to move saidmovable slats to open positions following the last step movement of saidrack in said one direction whereby allof said trays may be emptied, andmeans to eject all of the mats from said trays simultaneously when saidslats have been moved to open posi: tlons.

4. A fibre board machine comprising a conveyor movable-intermittentlyatregular intervals and on-which wet matsof fibre may be supported andmoved, an accumulator rack at the forward end of said conveyor includinga plurality of superimposed trays each adapted to receive and hold anindividual mat fed thereonto from said conveyor, a shutter mounted onthe forward end of said rack including a plurality of fixed slatspositioned to provide openings at the forward end of said trays andmovable slats adapted to move from and to 'open positions aligned withsaid fixed slats and shut positions bridging the openings between saidfixed slats, means inter.- mittently to' move said rack vertically-.shor.t steps in one direction whereby each atray may receive a matfrom .said conveyor, means to-move said rack back to its starting pointin one con.- tinuous movement, means to move said movable slats toshut-positions upon return of said rack, means to move said slats toopen positions following the last step movement of said rack in said onedirection whereby all of said trays may .abe emptied, and means to ejectall of the mats from said trays simultaneously when said slats have beenmovedto open positions, said ejecting means and rack returning meansbeing operable .successively and completely in an interval betweensuccessive movements of said conveyor.

5. A fibre board machine comprising a conveyor on which mats of fibremay be placed and fed forwardly, a vertically movable xaccumulator rackat the forward end of said conveyor for receiving said mats and holdingthem for subsequent insertion-into an adjacent hot press, saidaccumulator rack including a plurality of superimposed trays eachadapted to receive and hold an individual mat fed thereonto from saidcon.- veyor, and a shutter mounted on the forwardend of said rackincluding a plurality of relatively movable members forming a wall atthe ends of said trays when in one relative position and forming an opengrid to provide openings through which the mats may proceed into saidpress when in another relative position, said members when inwall-forming relation providing stops to arrestmove said movable grid togap closing position upon descent of said rack to its lower limitposition.

7. A fibre board machine comprising a conveyor on which wet mats offibre may be fed forwardly, a vertically movable accumulator rack at theforward end of said conveyor including a plurality of superimposed trayseach adapted to receive and hold an individual mat fed thereonto fromsaid conveyor, and a shutter mounted on the forward end of said rackincluding a fixed grid of slats so positioned as to provide gaps alignedwith said trays and a movable grid of slats each of sufiicient width tobridge a gap between adjacent slats of said fixed grid, the slats ofsaid fixed and movable grids being in sliding contact with each other toform an imperforate wall when in one relative position, means toreciprocate said rack between upper and lower limit positions, means tomove said movable grid to gap closing position upon descent of said rackto its lower limit position, a latch to hold said movable grid in gapclosing position as said rack is being elevated, and a solenoid torelease said latch.

8. The combination in a fibre board forming machine of a conveyor uponwhich wet mats of fibre may be intermittently moved forwardly, avertically movable accumulator rack at the end of said conveyor, saidrack including a plurality of vertically spaced mat-receiving means,means to elevate said rack intermittently in short steps to positioneach of said mat-receiving means opposite the end of said conveyorbetween successive movements of said conveyor, and means to control saidelevating means including a sensing plate positioned in the path of saidwet mats, a first switch movable in unison with said sensing plate to anopen position when said sensing plate is deflected by a wet mat and to aclosed position when the wet mat passes beyond said sensing plate, and asecond switch in series with said first switch and movable in unisonwith said sensin plate in one direction only as said sensing plate isdeflected by a wet mat.

9. The combination in a fibre board forming machine of a conveyor uponwhich wet mats of fibre may be intermittently moved forwardly, avertically movable accumulator rack at the end of said conveyor, saidrack including a plurality of vertically spaced mat-receiving means,means to elevate said rack intermittently in short steps to positioneach of said mat-receiving means opposite the end of said conveyorbetween successive movements of said conveyor, and means to control saidelevating means including a movable sensing member normally positionedin the path of said wet mats, a first control switch broken by saidsensing member when moved by a wet mat, means to return said firstswitch to closed position when said mat passes beyond said sensingmember, a second switch in series with said first switch andinterconnected in one direction of movement with said sensing member tobe moved to closed position when said sensing member is moved by a wetmat, and means on said accumulator rack for breaking said second switchupon completion of an upward movement of the desired extent.

10. The combination in a fibre board forming machine of a conveyor uponwhich wet mats of fibre may be intermittently moved forwardly, avertically movable accumulator rack at the end of said conveyor. saidrack including a plurality of vertically spaced mat-receiving means,means to elevate said rack intermittently in short steps to positioneach of said mat-receiving means opposite the end of said conveyorbetween successive movements of said conveyor, and means to control saidelevating means including a sensing member positioned in the path ofsaid wet mats, a first control switch including a contact moved to openposition by said sensing member when moved by a wet mat, means to returnsaid contact to closed position when said mat passes beyond said sensingmember, a second switch in series with said first switch and including asecond movable contact interconnected in one direction of movement withsaid sensing member to be moved to closed position when said sensingmemher is moved by a wet mat, and means on said accumulator for breakingsaid second switch upon completion of an upward movement of the desiredextent, said means to break said second switch comprising a plurality oflugs on said elevator rack spaced apart corresponding to the spacing ofsaid mat-receiving means.

- RALPH CHAPMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,776,201 St. Clair Sept. 16,1930 1,903,102 Farley Mar. 28, 1933 2,011,440 Dorn Aug. 13, 19352,171,922 Duval Sept. 5, 1939 2,200,708 Towne May 14, 1940 2,264,125Wolf Nov. 25, 1941 2,420,813 Camerota May 20, 1947 FOREIGN PATENTSNumber Country Date 433,778 Great Britain Aug. 15, 1935

